182: Renal Development

Question 1

Which germ layer gives rise to the kidneys?

Answer 1

Intermediate mesoderm

Question 2

What are the two key structures involved in forming the adult kidney?

Where do they come from?

What do they become?

Answer 2

• Ureteric bud
  
  • ​Arises from the nephric duct
  • Gives rise to collecting ducts, calyxes, renal pelvis, and ureter
• Metanephric mesoderm
  
  • ​Arises from nephrogenic cord
  • Interacts wtih the ureteric bud to form the glomerulus, proximal tubule, loop of henle, and distal tubule

Question 3

What is Potter’s syndrome?

What causes it?

Answer 3

Potter’s syndrome is the result of bilateral renal agenesis

• No kidneys
• -> oligohydraminos (not enough amniotic fluid)
• -> loss of fetal cushioning to external forces
• -> external compression of the fetus
• > abnormal development of the face and limb
• -> Altered lung liquid movement
• > Abnormal lung formation
• Often fatal

Question 4

The permanent kidney is the ______ reiteration of primitive kidneys that form in utero

Answer 4

The permanent kidney is the 3rd reiteration of primitive kidneys that form in utero

Pronephros, mesonephros, metanephros

Question 5

The metanephros arises from the ___________ and gives rise to the mature kidney

Answer 5

The metanephros arises from the intermediate mesoderm and gives rise to the mature kidney

Question 6

The ________ arises from the intermediate mesoderm and gives rise to the mature kidney

Answer 6

The metanephros arises from the intermediate mesoderm and gives rise to the mature kidney

Question 7

What structures to nephron progenitor cells (nephrogenic cord) give rise to?

Answer 7

Nephrogenic cord -> Metanephric mesenchyme ->

• Podocytes
• Bowman’s capsule
• Proxmial tubules
• Loop of Henle
• Distal tubules
• Connecting segments

Basically, everything except for the collecting ducts

(Nephric duct gives rise to colelcting duct and collecting system)

Question 8

A cyst in the midline below umbilicus (the navel) might be a remnant of which of the following?

A. Allantois

B. Ureteric bud

C. Mesonephric tubules

D. Urogenital sinus

E. Mesonephric duct

Answer 8

A. Allantois

Question 9

How many embryonic renal structures form in utero?

What are their fates?

Answer 9

Three embryonic renal structures form in utero

• Pronephros
  
  • Forms/degenerates week 4
• Mesonephros
  
  • Degenerates, contributes to the vas deferens in males
• Metanephros
  
  • Forms the permanent kidney
  • Appears week 5
  • Continues to develop through weeks 32-36

Question 10

What is renal agenesis?

What causes it?

Answer 10

Renal agenesis = failure of kidneys to develop in utero

• Ureteric bud fails to develop
• Does not properly signal to the mesenchyme
• Results in renal agenesis
  
  • May be bilateral -> Potter’s syndrome
  • or unilateral -> risk of focal segmental glomerular sclerosis -> renal faliure after decades

Question 11

Which embryonic structure are the glomerulus, proximal tubule, loop of Henle, and distal tubule derived from?

Answer 11

Metanephric mesenchyme

(interactions with the ureteric bud are critical for proper development)

Question 12

Renal agenesis may result from faulty development of what structure?

A. Cloaca

B. Paraxial mesoderm

C. Lateral plate

D. Intermediate mesoderm

E. Notochord

Answer 12

D. Intermediate mesoderm

The kidneys develop from the intermediate mesoderm

Question 13

Which structures does the primitive nephric duct give rise to?

Answer 13

Nephric duct -> Ureteric bud ->

• Collecting ducts
• Collecting system

(All other parts of the kidney arise from the nephrogenic cord)

Question 14

Which of the following is the first-functioning embryonic/fetal kidney?

A. Urogenital sinus

B. Pronephros

C. Mesonephros

D. Metanephros

E. Nephrogenic cord

Answer 14

C. Mesonephros

• The pronephros (B) forms first but is never functional
• The metanephros takes over from the mesonephros to form the permanent kidney

Question 15

Which of the following sentences is correct?

1. The ureter arises from the cloaca
2. The nephron progenitor cells give rise to Bowman’s capsule, the proximal and distal tubules, and the podocytes
3. The metanephric mesenchyme gives rise to the collecting ducts
4. The ureteric bud gives rise to the distal tubules
5. The metanephric mesenchyme gives rise to the nephron progenitor cells, collecting ducts, and collecting system

Answer 15

b.

The nephron progenitor cells give rise to Bowman’s capsule, the proximal and distal tubules, and the podocyte

Question 16

Which two distinct cell lineages does the metanephros arise from?

Answer 16

Uretic bud

Metanephric mesenchyme

Question 17

What structures does the colaca give rise to?

Answer 17

The bladder and rectum

Question 18

What are some of the signs of a baby born with Potter’s syndrome?

Answer 18

Limb deformities

Flat face

Pulmonary hypoplasia

Often fetal death

Question 19

Which embryonic structure are the collecting ducts derived from?

Answer 19

Ureteric bud